Substance use refers to the use of alcohol or drugs, including substances like nicotine, caffeine, prescription drugs, and illegal drugs. Substances make us see, think, feel and behave differently than we usually do.
Substances can be classified as:
- legal (For example: caffeine, over-the-counter drugs like Tylenol 1 [opioid])
- legal but regulated (For example: nicotine, alcohol, cannabis, prescription drugs like Tylenol 3 [opioid])
- (Note: Most of the substances listed above are illegal for youth under 18-19 years old in BC)
- illegal (For example: heroin [opioid], cocaine, ecstasy)
Types of substances:
- opioids - such as heroin, fentanyl or prescription drugs such as Oxycontin
- cannabis - also called pot or weed
- depressants - also called downers (alcohol, Xanax, Valium, barbiturates)
- stimulants - also called uppers (cocaine, speed, nicotine)
- hallucinogens - also called psychedelics (magic mushrooms and LSD [acid])
The effect any substance can have on a person depends on:
- the type of substance (for example: depressants, stimulants)
- individual factors (for example: age, past experience, genes)
- the context (for example: how much, how often, other drug use)
- why they are using the substance (see below for more information)
Why do youth use substances?
People have used substances for thousands of years and for many different reasons, including those in this graphic:

Adapted from: https://www.heretohelp.bc.ca/infosheet/understanding-substance-use-a-health-promotion-perspective
Substance use is a complicated behaviour. It's important to consider everything that may influence a youth’s choice to use substances. These factors may include:
- Social Disconnection. Youth may use substances if they don’t feel attached to family, school and community. Feeling connected can strongly protect and help to lower the chance of a youth using substances in problematic ways.
- Existing Conditions. Some youth are more likely to take risks than others, because they have low impulse control, high sensation seeking or conditions like bipolar disorder or fetal alcohol spectrum disorder (FASD).
- Mental Health and Coping. Some youth start to use substances to help them cope with stress, anxiety or depression. Youth who are dealing with complex trauma or emotions may turn to substances. There may be conflict at home, school or among their peers. Using substances may be a form of relief or escape. Sometimes early substance use is linked to eating disorders. Youth may begin using substances such as nicotine because they think it will lower their appetite or control their weight.
- Discrimination. Youth may use substances to deal with stress and unfair treatment because of factors including:
- race
- sexual orientation
- gender identity
- cultural identity
- age
As a result, they may be experiencing low self-esteem, shame or guilt. They might be worried about being left out or discriminated against. They may feel invisible, unheard and powerless.
- Self-medicating. Youth may use substances to self-medicate as a way to deal with physical and emotional pain. It may help to dull emotional pain or make the condition seem more manageable, but the effect is only temporary.
- Social Influences. Youth are exposed to many different influences every day. Some influences may make substance use look cool and fun and with little consequence. From friends and peers to technology and social media - there are many opportunities for youth to learn about or witness substance use. Your child may become curious about substances, want to fit in or feel pressure to use substances.
- Looking to teach your child how to deal with peer pressure? Check out these tips.
How substance use can become a problem
It is normal for youth to experiment, but substance use can become a problem if it starts to interfere with daily life and mental health. It’s important to recognize the different stages of substance use and pay attention to your child’s mental health.
These are the stages of substance use:

If someone has a substance use problem and a mental illness at the same time, they have what’s called a concurrent disorder - one example is experiencing both depression and alcohol dependence. You can listen to our podcast episode on concurrent disorders here.